babbows



April 29 1924.

G. s. BARROWS ET AL SAFETY CONTROLLER FOR GAS VALVES Filed Jan. 2. 1920Patented pr. 29, 1924.

MTED STATES PATENT OFFICE.

GEORGE S. BARROWS. OF PROVIDENCE, RHODE ISLAND, AND NICHOLAS W. PARK,OF`BROOKLYN, NEW YORK.

SAFETY CONTROLLER FOR GAS VALVES.

Application tiled January 2, 1920. Serial No. 348,857.

To all whom t may cmwe'm:

Be it known that we, GEORGE S. BARROWS and NICHOLAS W. PARK, citizens ofthe United States, respectively, residing at Providence, in the countyof Providence and State of Rhode Island, and at Brooklyn, in the countyof Kings and State of New York, have invented certain new and usefulImrovements in Safety Controllers for Gyas alves, of which the followingis a speelfication.

This invention relates to flame-controlled gas valves. More particularlyit relates to safety devices for gas burners, in which the ignition ofgas is dependent on the existence of a flame at the orifice, which maybe either the main flame or a pilot iame. Such a flame may beex-tinguished by wind, by temorary drop in gas supply pressure, or evenEy malevolent interference, following which the gas supplied to theburner upon a restoration of pressure or when turned 'on automaticallyas by a thermostat, or otherwise, will fail to be ignited, perhapsVwithout the knowledge of any person, with ensuing disagreeable ordamaging results. It 1s the object of the invention. to prevent such byautomatically preventing the flow of as unless the igniting fiame isburning. e objects of the invention are accomplished by arranging avalve which controls the as supply in combination with means tendingautomatically to close it and means by which the igniting iame producesa reaction that holds the valve open automatically to permit the passageof gas while the fla-me is burning. This means embodies an electricalcircuit which is made or broken by the movement of a thermostatic memberactuated by heat from a iiame predetermined as proper. It is part of theinvention to construct the thermostat so that it is neither subject tothe corrosion and distortion which results from being in thev ame, norsubject to the uncertainty which attends the direction and intensity ofradiation of heat from the flame; but is nevertheless so arranged as tobe dul sensitive to the iiame. It is a further o ject to make theapparatus of such a type that it can be light in weight, contained insmall compass near the ame, and well protected. These and other objectsare accomplished by supporting the thermostat on the pilot tube, withina screen and arranged to receive heat by conduction from the iiame, andto bend into contact with the pilot tube or other metallic element thatconducts the heat to it from the flame and also serves as a conductor ofelectricity to control the as valve and hold it open. When the pilotflame is not burning, the thermostatic element moves out of contact,thus breaking the circuit and letting the gas valve automatically close.The thermostat, being thus set so as to make the contact only whenextremely hot from the direct conduction of heat, is further protectedfrom acquiring a permanent distorted set from its coolings by a stopwhich limits its movement on cooling to a short distance, only greatenough to make a good break. The invenl tion may be embodied in otherarangements, some of which are set forth hereinafter. It is intendedthat the patent shall cover, by suitable expression in the appendedclaims, whatever features of patentable novelty exist in the inventiondisclosed.

In the accompanying drawin Figure 1 is a side elevation offlsa fragmentof a radiator embodying the invention partly in diagram;

Figure 2 is a similar view on a larger scale of the safety thermostatand associated parts in medial section;

Figure 3 is an e-levation of the end of the apparatus of Figure 2; and

Figures 4, and 5 are side elevations in medial section of modifications.

Referring to the drawings, which represent the invention arranged incombination with a gas radiator, having a burner set in the open air, sothat escape of gas from the burner without ignition would introduce thegas into the apartment, 10 indicates the burner and 11 the radiatortubes. For igniting the gas whenever it is turned on, a pilot ame 12supplied by a pilot tube 13 is provided, the main supply of gas to theburner 10 coming through the mixing device 14 from a gas supply pipe 15.Controlling the supply is a gas valve 16 tending always to fall againsta seat 17 from which it may be lifted by the armature 18 of a magnetwithin the casing 19 whenever a current passes through the circuit 20.Such a current, from any suitable source, such as a low potentialgenerator 21, may include in its circuit a serving thermostat 22 set inthe apartment whose temperature is to be controlled automatically,arranged to close the circuit when the lll temperature of the room fallsto apredetermined point, thereby energizing the magnet and opening thegas valve, assuming that the circuit is complete elsewhere. These partsmay be ot' any suitable or ordinary const-ruction, but it is a featureot the invention that the circuit is through a safety thermostatoperated by the flame.

In the particular forni illustrated in F igure 1, the main length ofpilot tube 13 terminates far enough from the pilot burner orifice 2l tocarry a block of insulatingr material 23 and a screen housing withinwhich is an insulated tip or continuation 13 of the pilot tube, and thesafety thermostat 2G. 'lhe thermostat there illustrated is a lightbi-metallic bar bentinto U-shape with one limb of the U held in theinsulating block by a set screw to which an external wire of the circuitis attached, and with the other end 29 of the U adapted to make contactwith the insulated tip -section 13 of the pilot tube 13 which in turn isconnected through screw 31 to another external n wire 2t) of thecircuit. The screen 25 may be a tubular, fine mesh cap held on the sameblock of insulating material by any convenient device, as by friction,with its closed outer end so ositioned that the tip of the pilot tubeand) its flame are close outside of it. The curved part of the U may beclose to the flame, but within the screen. Experiment has disclosed thatit is bad for the thermostat to stay in the flame; and that even if itbe closely adjacent to the flame, with the heat reaching it byconvection and radiation from the flame, its action is uncertain. Thearrangement illustrated, however, While availing of such help as maycome by way of radiation, provides as a main and certain element of thecombination a direct metallic connection from the flame to thethermostat. This connection is the tube tip 13', through which heatflows by conduction from the flame and the rate of such transfer of heatis fairly constant. f The screen permits circulation of air pastthethermostat but slowly. Corrosion of the thermostat is reduced because itprevents to a great extent products of combustion from the flame, andmoisture from the atmosphere reaching the thermostat. A stop or screw 31mounted on one limb of the thermostat prevents the other limb fromdeparting more than the necessary short distance from its position ofcontact with the pilot tube tip 13', and thus prevents any distortionoccurring upon cooling. For clear-ness, this is the positionillustrated. notwithstanding that the flame is indicated as burning.

To start operation, there being no flame wit-hin at the pilot burner orthe main burner, the pilot flame may be ignited with a match-or by anysuitable means, and burned alone until the thermostat is heatedsuiciently to make and maintain the heat conducting contact. This occursin a short time, ordinarily, and may be expedited by holding a matchdirectly under the thermostat. Thereafter suflicient heat to maintainthe contact reaches the'thermostat by conduction through the pilotburner tip section, when added to that comingr by radiation from theflame and from the adjacent screen. The circuit is thus maintainedcontinuously in condition for the gas valve to be open, so long as thepilot flame 12 is burning. During this situation, the valve 16 may,however, be closed and opened ad libitum, either by hand, orautmatically by the thermostat 22, or otherwise; and whenever that valveopens the gas that then flows out through the burner 10 will find thepilot flame 12 burning and ready to ignite it. But if for any reason thepilot flame 12 is extinguished, the thermostat 26 promptly opens thecircuit between its point 29 and the pilot tube 13'; and while thatcondition continues no current can pass through the circuit 20 to openthe gas valve 16.

Figure 5 shows a form in which the heat is conducted from the flamethrough a separate rod or tube to the thermostat tip. In this case, thepilot tube is not a part of the circuit. The circuit may be furthersimplified, if desired, by making the tip continuous with the body partof the pilot tube. as indicated in Figure 4. In this case, the body ofthe tube and valve casing constitute part of the return circuit which isgrounded thereto.

Although theidea is illustrated as it may be used in connection with apilot flame, whose normal function it is to be continuously burning, andagainst whose extinction the device is a safeguard, it may be applied toany other sort of a. gas flame. as for example, to a main burner, forprotection in case of occurrence of a depression or cessation of mainsupply pressure' suflicient to extinguish the flame, followed by arestoration of such pressure.

We claim as our invention 1. The combination, with a gas burner and aservice gas valve, of means to hold the valve open; and a thermostatcontrolling said means; there being an element arranged to conduct heatto said thermostat from a flame associated with but independent of saidburner; the said valve being arranged to close automatically whennotheld open by said thermostatically controlled means.

2. The combination, with a gas burner and a service gas valve, of `meansto hold the valve open; and a. thermostat controlling said means; therebeing a strip of metal extending to the thermostat from a flameassociated with but independent of said burner and conducting heat tosaid thermostat; the said valve being arranged to close automaticallywhen not held open by said thermestatically controlled means.

3. The combination, with a gas burner and a service gas valve, of meansto hold the valve open; and a thermostat controlling said means; therebeinga tube for conducting gas to a pilot flame associated with saidburner; the tube and thermostat being arranged for heat to flow byconduction through the tube from its llame to the thermostat; and saidvalve being arranged to close automatically when not held open by thethermostatically controlled means.

4. The combination, with a gas burner and a gas valve, of means to holdthe valve open; and a thermostat controlling said means; there being atube for conducting gas to a pilot flame associated with said burner;the tube and thermostat being arranged for heat to flow by conductionthrough the tube from its llame to the thermostat; and said valve beingarranged to close automatically when not held open by thethermostatically controlled means; the said pilotvtube having anelectrically insulated heat and electricity conducting tip portion; andthe said control means includmg an electric circuit of which said pilottube tip is a part.

5. The combination, With a gas burner and a service gas valve, of meansto hold the valve open; a thermostat controlling said means, arranged toreceive and be actuated by heat from a flame associated with butindependent of said burner; and means tending to retard escape of heatfrom said thermostat but not from the burner; the said Valve beingarranged to close automatically when not held open by saidthermostatically controlled means.

6. The combination, with a gas burner and a gas valve, of means to holdthe valve open; a thermostat controlling said means and arranged to beactuated by heat from a flame associated with but independent of saidburner; anda screen encasing said thermostat, closely adjacent to theflame, conducting heat from the flame to the space around the thermostatand retaining heat of the thermostat; the said valve being arranged toclose automatically when not held open by said thermostaticallycontrolled means.

7. The combination, with a gas Aburner and a gas valve, of means to holdthe valve open; a thermostat controlling said means yand arranged to beactuated by heat from a flame associated with but independent of saidburner; and an enclosure for the thermostat apart from the burnerreducing the circulation of air thereabout; the said valve beingarranged to close automatically when not held open by saidthermostatically controlled means.

8. The combination, With a gas burner and a gas valve, of means to holdthe valve open; a thermostat controlling the said1 means, arranged to beactuated by heat from a llame associated with said burner; theV saidvalve being arranged to close automatically when not held open by saidthermostatically controlled means; and a stop adapted to engage thethermostat and prevent all but the initial,

part of the movement thereof which it tends to make when the llame isextinguished.

9. The combination, in a radiator, of heat radiating tubes; a gas burnerset with gas therefrom escaping into the open air, and With openingsarranged under the radiating tube entrances whereby normally gases fromthe burner flame are carried into said tubes; a valve controlling thesupply to said burner; a pilot flame tube leading from the gas supply,before the valve, to a tip associated with said burner; said valvetending automatically to close; and means to hold the Valve open, havinga thermostat controlling it, said thermostat being arranged to beactuated by heat from said pilot llame.

Signed at Providence, Rhode Island, this 27th day of October, 1919.

GEORGE S. BARROWS. NICHOLAS W. PARK.

